The role of MEG in pre-surgical evaluation of epilepsy: current use and future directions.

Identification of the epileptogenic zone is a critical determinant of seizure control outcomes following surgical resection in medically refractory seizures. There has been increasing recognition of the contributive value of Magnetoencephalography (MEG) studies in the diagnostic evaluation of epilepsy. Biomagnetic signals recorded by MEG studies in combination with source modeling techniques can yield diagnostic information regarding the underlying epileptogenic zone. MEG evaluation is particularly useful in evaluation of non lesional neocortical epilepsy. In these cases, MEG spike sources can guide presurgical and perioperative invasive monitoring. The incorporation of MEG-based diagnostic information into the surgical evaluation and management plan has consistently been shown to be associated with improved seizure control outcomes.